1. Technical Field
The present invention relates to a gaseous fuel injector assembly and, more particularly, to a solenoid valve assembly for a fuel injector particularly suited for use in a dry gaseous-fueled vehicle such as a hydrogen-powered vehicle.
2. Background
Solenoid-actuated valve assemblies, generally known as xe2x80x9csolenoid valve assembliesxe2x80x9d, are widely used in a multitude of applications including fuel injection systems. The typical solenoid valve assembly of interest herein includes a housing assembly in which is disposed a solenoid and a valve assembly in axial alignment with one another. The solenoid includes a coil, a stationary pole piece or stator, and a movable plunger including an armature and a drive pin. The plunger extends axially through a bore in the pole piece such that, upon energization or deenergization of the coil, the plunger moves axially to open and close a valve element of the valve assembly. A great many solenoid valve assembly designs are available, with the design details being tailored to meet the needs of a particular application.
One example of a fuel injector assembly is shown in U.S. Pat. No. 5,752,689, which is hereby incorporated by reference. Typically, such valves are used in with compressed natural gas systems which have at least some compressor lubricant. A hydrogen gas source, however, does not have any lubricant therein. Therefore, one problem with the embodiments in the xe2x80x3689 patent is that when used with dry fuels such as hydrogen, excessive wear is present in the moving portions of the injector.
It would therefore be desirable to provide a fuel injector assembly system that allows use with dry fuels such as hydrogen.
The present invention is a solenoid valve assembly that exhibits increased durability when compared to similar prior solenoid valve assemblies.
A fuel injector system according to the present invention has a housing having a valve assembly disposed therein. A solenoid is also disposed within the housing. A valve assembly is disposed between an inlet port and an outlet port. The valve assembly has a valve seat having an opening therein. A drive pin extends at least partially through valve opening. A stop has a spring thereon. A valve element is urged against the valve opening by spring. The drive pin is at least partially coated with a lubricating coating. In the preferred embodiment at least a concave surface of drive pin is coated. In addition, a concave surface of stop may also be coated. In addition, a spring seat of stop may also be coated with a lubricating coating as well.
One advantage of the invention is that the life of the fuel injector for dry fuels is increased.
Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.